Spatial and temporal analysis of debris flow occurrence in three adjacent basins of the western margin of Grande River: Quebrada de Humahuaca, Jujuy, Argentina

ESPER ANGILLIERI, MARIA; - PERUCCA, L.; NICOLÁS, VARGAS

GEOGRAFISKA ANNALER SERIES A-PHYSICAL GEOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020

0435-3676

Numerous slides, rock falls and flows occur in the arid mountainous areasof northwestern Argentina. On 10 January 2017, torrential rain caused theacceleration of large-scale and slow-moving landslides mainly in the LosFiltros basin and it produces important damage in the Volcán villagecausing fatalities, dozens of evacuees and great economic losses, withthe total destruction of buildings, services and infrastructure. However,in the two adjacent creek basins, the Coiruro basin to the north and DelMedio basin to the south, the effects were smaller. A morphometricanalysis of these three adjacent basins was carried out in order tounderstand this catastrophic event and to explore its causes. Thegeological characteristics of the study basins are very favourableconditioning factors in landslide generation. Precambrian-age low grademetaclastics shatter in the frost climate of the higher mountains andpoorly consolidated Quaternary deposits along the sides of the gullyerode readily and become source material for landslides. Also, the area,shape, relief and slope of the basins would have been other key factorsin the debris/mud flow generation in the Los Filtros creek basin. TheMelton ratio number has been a key morphometric index todiscriminate river basins susceptible to different types of flows. Finally,this study aims to increase knowledge of all the above-mentionedevents in order to provide several methods of analysis for landslideprevention and control in adjacent basins whit different dynamics in theCentral Andes.